The present invention is directed generally to the door lock and latch mechanism arts, and more particularly to a unique operator comprised of two cams, each individually operated to cause a latch bolt to move between outwardly extended and inwardly retracted positions.
Door latch assemblies are available to enable one to lock and to release the assembly from one side of a door utilizing a push button key. These latches find use with bathroom and bedroom doors. For the most part, these assemblies possess the desireable features of movement of the door handles or knobs independently of one another and also provide for release of the locking mechanisms by rotation of the inner door handle or knob in either clockwise or counterclockwise direction. Door latches possessing these features are, however, for the most part complex, expensive to manufacture and difficult to install. Moreover, presently available door latches with the push button key locking feature, for use on bathroom or bedroom doors, are comprised of mechanisms which as a whole do not lend themselves to repair, such that upon the occurrence of a fault or a breakdown of the mechanism, it is necessary to replace the entire assembly. Other door latches of more simple construction do not possess the locking feature.
In U.S. Pat. No. 4,720,127 there is described a door latch having an elongated stationary case. A latch bolt is mounted to reciprocate longitudinally in the case between outwardly extended and inwardly retracted positions. An operator within the case is rotatable about an axis extending transversely through the case to cause a driver to move the latch bolt longitudinally in response to rotation of the operator. The driver includes a latch slide which is urged to a forward position in the case by means of a compression spring. The operator is comprised of a first cam and a second cam, each having top and bottom portions engaging the driver to enable the driver by rotation of the operator in either a clockwise or counterclockwise direction. A push button key is provided moveably mounted to a sidewall of the case and moveable in the direction into and out of the case without engaging the second cam. The first cam has a portion for receiving at least a part of the push button key for locking the first cam against rotation when the key is in the receiving portion. With the key in the receiving portion, the first cam is locked against rotation and therefore the door latch cannot be operated from the outside of the door to which the latch is mounted. The second cam has a camming means formed in the surface adjacent the sidewall of the case and receives a pin mounted on the push button key such that the rotation of the second cam will engage the pin and move the push button key out of the receiving portion of the first cam. This effectively unlocks the door and permits the opening and closing of the door from either side.